Refrigeration system



March 19, 1929. s. HILGER REFRIGERATION SYSTEM Filed Dec. 24, 1925Patented Mar. 19, 1929.

UNITED STATES GEORGE HILGEB, OF CHICAGO, ILLINOIS.

REFRIGERATION SYSTEM.

Application filed December 24, 1925. Serial No. 77,444.

The invention relates to a refrigeration system and has for its generalobject the provision of improved means for controlling the flow ofrefrigerant to the expansion coil or coils. I a

An especial object is to provide a regulating valve for use inrefrigeration systems operatingin response to variations in thetemperature of a room or chamber being refrigerated and which, whilepositive in operation, is extremely sensitive to temperature changes.

Still another object is to provide a regulating orcontrol valve in whichthe valve member is operated by a differential in pressure bet-ween twoopposed pressure responsive elements, one of which is responsive to roomtemperature and the other of which is responsive to the pressure of therefrigerant flowing to the expansion coil, a condition of balancebetween the opposed forces obtaining at the desired room temperature;

A general object is to provide a control valve which is simple inconstruction and ex-.

ceptionally durable in character.

Figure 1 of the drawings is' a view partially diagrammatic in characterillustrating a refrigeration system embodying my invention.

Fig. 2 is a vertical sectional view on an enlarged scale through theregulating valve.

The system is herein shown as applied-to two cooling rooms or chambers Aan containing an expansion coil 3 having one end connected with a supplyline 4 and the other end connected with a return line 5. Refrigerant issupplied to the supply line 4 in the operation of a suitable compressor6. 7 is a condenser of ordinaryconstruction and 8 a liquid receiver. Thesupply of refrig erant to the line is under the control of an expansionvalve'9 which-is preferably of the automatic constant pressure type.

Interposed in the connection between the supply line 4 and the expansioncoil 3 of each of the chambers is a regulating valve generallydesignated by the numeral 10. This valve is arranged to be operated by adifferential in pressure between the pressure of the refrigerant flowingto the coil 3, and

the pressure of a temperature responsive pressure device generallydesignated by the numeral 11.

The valve 10 (Fig. 2) comprises a casing 12 having a passagewaytherethrough controlled by a valve member 13. The casing has atransverse partition 14 therein constructed to provide a verticallydisposed port 15 formed in a threaded member 16, the

latter providing a valve seatl? for the 'valve member herein in the formof a ball 13. The upper portion of the member 16 is con structed toprovide a cage 18 loosely receiving the ball. The inlet port 19 opensinto the valve casing'above the partition 14, and the outlet 20 leadsfrom the valve casing from a point below the transverse partition 14 anddiametrically opposite the inlet port 19. o

The valve member 13 is normally held to its seat 17 by a coiledexpansion spring 21, acting at its lower end upon a flanged block 22adapted to rest upon the ball, and at its upper end-upon a similarlyflanged block 23 vertically adjustable by means of a screw 24. Forreceiving the spring 21, the screw 24 and associated parts, the valvecasing has a bonnet 25 screw-threaded into the upper end of the casingand constructed to provide a chamber 26 for the spring and its pressureblocks 22 and 23. The screw 24 is threaded into the upper end of thebonnet as indicated at 27 and bears in a central recess 28 in the upperend of the block 23. The screw 24 has an operating stem 29 projectingthrough a suitable stufling box 30 and squared at its upper end 31 toreceive a ring or the like.

The means for operating the valve member 13 to regulate the flow ofrefrigerant through the valve casing 12 is, as above indicated, underthe controf of the temperature responsive device 11. To this end Iprovide a pressure responsive element or plate 32 operatively associatedon the one hand with the valve member 13 and responsive on the otherhand to the pressure device 11. This pressure plate 32 is enclosedwithin and normally rests upon the bottom of a chamber 33 connected witha hollow cylinder 35 by a pipe 34 opening into the bottom of thechamber. This 'cylinder is adapted to contain a charge of ammonia orother temperature responsive element and constitutes the pressure device11.

The chamber 33 is in the lower end of the valve structure, and is formedby means of an annular casing 36 having a bottom wall 37 enclosed at itsupper end by the bottom wall 38 of a hollow spacing member 39 whichlatter has a top wall 40 to. which is secured the lower end of the valvecasing 12.

. adapted to move vertically. Said block 42 has a central pin 43projecting upwardly 1 into the valve port 15 and adapted to engage withthe valve member 13.

Pressure imparted to the plate 32 in the chamber 33 is transmitted tothe valve member through the pin 43, block 42 and a spacer pin 44. Atits lower end. said pin 44 bears in a recess 45 centrally of the plate32 and passes upwardly through a tubular member 46 extending centrallythrough the annular spacing member 39, theupper end of the pin bearingupon the underside of a plate 47 centrally thereof. To prevent thepassage of pressure upwardly from the chamber 33 T preferably employ abellows diaphragm 48 of which the plate 32 herein forms the bottom wall.The top wall of this diaphragm is formed by a plate 49 having a centralnipple 50 therein screw-threaded into the bottom wall 38 of the annularspacing member 39. Similarly, to prevent the escape of pressure from thevalve casing 12, T provide a bellows diaphragm 51-of which the plate 47forms the upper wall and a plate 52 forms the bottom wall. The plate 52has a central nipple 53 screw-threaded into the top wall 40 of theannular chamber 39.

These bellows diaphragms, it will be ob served efi'ectually prevent theescape of pressure from one chamber to the other. They eliminate thenecessity of using a stuifing box, which is objectionable because itwould interfere with and frictionally restrain the movements of the pin44. This is especially true in the case'of valves used for refrigerationpurposes because'the sliding stem would become coated with ice and tendto freeze in the packing.

Also it will be observed that the bellows diaphragms permit of a widerrange of movement without strain such as is incident to the useof asimple or plate diaphragm.

It will be observed that the pressure element formed by the plate 32 ismade substantially larger than the pressure element formed by the plateor block 42, and the arrangement is such that when the temperature ofthe room being cooled is at a predetermined point the spring 21 coactingwith the pressure on the upper element 42 will balance the pressure onthe lower ele* ment 32 and any further lowering of the temperature inthe room will permit the valve member to be held to its seat thusentirely cutting off the flow of refrigerant to the coil. The spring inthis arrangement may be relatively light because it is assisted inopposing the force applied to the lower pressure element by the pressureflowing through the valve.

For charging the hollow cylinder 35 I preferably provide a valvedconnection between the inlet side of the valve casing and the pipe 34leading to the cylinder 35. This connection in the present instancecomprlses l a pipe 54 opening into the valve casing at 55 above thetransverse partition 14 and opening into the pipe 34 below theregulating valve 10. By the manipulation of a hand operated valve 56interposed in the pipe 54 a charge of ammonia may be admitted to andthen confined in the cylinder 35. If desired a gage 57 may also beprovided in the pipe 34 adjacent the cylinder 35 to indicate thepressure and hence the temperature in the room I perature in either ofthe chambers to its predetermined point will not interrupt the operationof the motor 58 but the lowering of the temperature in both of thechambers will interrupt the operation of the motor.- Herein I have shownthermostats 59 and 59' in the respective chambers. The thermostat 59 islocated in the chamber A and is interposed in a circuit 60 connected inone side of the line leading to the motor. The thermostat 59 is locatedin the chamber B and interposed in the same side of the line. It will beobserved that so long as the temperature in one of the chambers remainsabove the predetermined point, the circuit to the motor is maintainedand only upon the lowering of the temperatures in both chambers to thedesired points is the circuit interrupted.

In the operation of the system, refrigerant is supplied to the pipe line4 under the control of the expansion valve 9 operating to maintain asubstantially constant pressure in the supply line. Initially thetemperatures in the chambers A and B being above the points desired, theregulating valves 10 permit the flow of refrigerant through theexpansion coils 3 to the return line 5. This is due to the fact that thepressure of the element in the thermo-responsive cylinder 35 issufficient when applied to the pressure element 32 to overcome thepressure on the element 42 plus the tension of the spring 21.

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As the temperature in one of the chambers It will be seen that the valvemember is operated by a differential in pressure varying with thetemperature of the chamber being cooled, and with only a slight rise intemperature the differential increases rapidly with the result that thevalve member is positively operated. Thus the regulating valve isextremely sensitive and is capable of maintaining the temperature in thechamber substantially constant.

' The thermostat for controlling the motor circuit may be adjusted so asto be operative just prior tothe complete shutting off of the flow ofrefrigerant to the coil in the proper chamber.

It will be observed that by a relatively simple construction, I haveeliminated troublesome stufling boxes, increased the durability of thevalve and at the same time substantially increased its operatingefliciency.

I claim as my invention:

1. A regulating valve for refrigeration systems having two opposedpressure elements one arranged to be subjected to the pressure of therefrigerant flowing through the valve and the other arranged to besubjected to an independent and variable prespin.

sure, the last mentioned element being of larger eflective area than theother element and the pressure in either chamber being independent ofthe pressure in the other chamber, and valve means operable by theeffective pressure differential between the two elements, the smallerpressure element having spring means operatively associated therewithcoacting with the pressure on the smaller element to balance atapredetermined point the pressure on the larger element.

2. A regulating valve for refrigeration systems comprising, incombination with a valve member to be operated, of operating meanstherefor including two opposed imperforate pressure elements each in theform of a rigid member, means providing separate chambers for saidmembers, insulation means between said chambers, a pin interposedbetween said members and extending into the respective chambers, andbellows diaphragms associated with. ,the respective members to preventcommunication of'pressure between the two chambers around said 3. In aregulating valve for refrigeration systems, the combination with a.valve member to be operated, of operating means for the valve memberincluding a pair of pressure responsive members, chambers in firstmentioned chambers, and means operatively associated with the respectiveelements to prevent commumcation between the pressure chambers throughsald tubular stem.

a 4. A regulatmg valve for refrigeratlon systems and the likecomprising, in com bination, a valve casing having a partition thereinwith a valve port in said partition, a spring-pressed valve membertending to, close said port, said casing on opposite sides of thepartition having inlet and outlet ports respectively for refrigerant,means forming with said valve casing a closed chamber communicating withsaid inlet port, a pressure element operatively associated with thevalve member and movably mounted in said chamber so as to respond to thepressure of the refrigerant therein, means providing a second closedchamber in spaced relation to the first chamber, a second pressureelement. in said second chamber of substantially larger area than thefirst pressure element, said second chamber being adapted for connectionwith a source of thermally responsive pressure fluid, a spacer betweensaid two elements whereby said elements move in unison, and a partitionincluding insulation material, interposed between said two chambers andhaving an opening therethrough for said spacer. Y

5. A. regulating valve for refrigeration systems comprising, incombination with a valve casing adapted for connection with a sourcev ofrefrigerantand having a valve member therein, and means for controllingthe operation of said-valve member comprising-a chamber communicatingwith the source of refrigerant, a second chamber communicating with asource of thermally responsive pressure fluid, a' pressure elementmovably mounted in each of said chambers In testimony whereof, I havehereunto 'afiixed my signature. I

GEORGE HlILGER.

